Comment 29 for bug 1659172

Ah, sorry, I misread...
So basically 64-bit versions have shown to be problematic, which is probable as they're based on a completely different build system (mingw vs mingw-w64, where the -w64 does not simply mean "64-bit" but is a significantly diverged fork of the former).

I'm not sure if the further differentiation into execution type / privileges really can be trusted as there seem to be additional factors involved, e.g. you noted different behavior depending on wether you launched Inkscape on a command line before or not. I'm not sure if this really can affect the Inkscape process directly (it should not as far as I know) unless we change environment (which I'm pretty certain we do not; it can be quickly checked by executing the "set" command to print all environment variables before and after running Inkscape and on my system the output is identical). So I'm really suspecting something very fundamental...

If you (or somebody else who's frequently experiencing hangs) could test the newer MSYS2 builds that could be helpful. They're also based on mingw-w64 (this time both 64-bit but also 32-bit builds) but use significantly newer library versions and some additional patches/fixes which were not included in the mingw-w64 build currently used for stable releases.